linux-kernel - Re: [PATCH v2] gpiolib: allow poll(2) on gpio value

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Date:	Thu, 2 Jul 2009 14:15:29 +0300
From:	Jani Nikula <ext-jani.1.nikula@...ia.com>
To:	David Brownell <david-b@...bell.net>
Cc:	Daniel Glöckner <dg@...ix.com>,
	Ben Nizette <bn@...sdigital.com>, linux-kernel@...r.kernel.org
Subject: Re: [PATCH v2] gpiolib: allow poll(2) on gpio value

On Thu, Jul 2, 2009 at 2:05 AM, David Brownell<david-b@...bell.net> wrote:
> On Wednesday 10 June 2009, Daniel Glöckner wrote:
>> Many gpio chips allow to generate interrupts when the value of a pin
>> changes. This patch gives usermode application the opportunity to make
>> use of this feature by calling poll(2) on the /sys/class/gpio/gpioN/value
>> sysfs file. The edge to trigger can be set in the edge file in the same
>> directory. Possible values are "none", "rising", "falling", and "both".
>
> Looks pretty clean.  Comments from anyone else?

I'd appreciate a kernel side interface to gpio_setup_irq functionality
as well; now gpio_export from kernel won't setup support for poll(2)
nor is there any possibility to do so. Having said that, it can be
done in another patch, another day, I don't want that to be holding
this patch back.

And I guess it might also be argued that anyone wanting to poll(2) can
setup edge triggering from user space when needed. Other thoughts on
that?


BR,
Jani.
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/